When I plug a fat32 formatted memory stick into any of our computers it opens up and works fine, but their is one computer that if i connect it to always says that the disk needs to be formatted, and if i try and format the disk as fat32 on the computer it just says that the format couild not be completed!

I have tried formatting the usb key to ntfs and this works fine, but it means that nobody can plug any fat32 memory sticks into the computer otherwise they need reformatting to ntfs.

Make sure that you are removing the USB drive properly by stopping it first. It could be that there's something picky on that particular machine keeping it from reading. You could also try going into device manager and deleting USB Mass Storage Device while the drive is plugged in, remove it and reboot, then try plugging it in again.